Effects of doping on the superconductivity of the Bi1.84Pb0.34Sr1.91Ca2.03Cu3.06Oy oxide (original) (raw)
Related papers
Preparation and Characterization of Hot-Pressed and Sintered BiPbSrCaCuO Superconductor
New Journal of Glass and Ceramics, 2012
Powder compacts of the system Bi 2-x Pb x Sr 2 Ca 2 Cu 3 O y with 0 ≤ x ≤ 0.5 molar ratio using both techniques; isothermal hot pressing and the solid state reaction (sintering). The XRD of the hot pressed powder compacts of the nominal compositions Bi 2-x Pb x Sr 2 Ca 2 Cu 3 O y showed 2212 and 2223 phases. The resistivity temperature variations belonging to the composition Bi 1.8 Pb 0.2 Sr 2 Ca 2 Cu 3 O y showed metal-superconducting transition at T ons = 143 K for the annealed sample for 24 h. The annealed nominal composition Bi 1.5 Pb 0.5 Sr 2 Ca 2 Cu 3 O y for 18 h showed metal to superconducting transition at 80 K.
The effect of Ag-doping on the magnetic behaviour of Bi–(Pb)–Sr–Ca–Cu–O ceramic superconductors
Journal of Alloys and Compounds, 1998
AC susceptibility x9(T, H) and x0(T, H) measurements have been carried out on rectangular bar shaped high-temperature ac ac superconductors with nominal composition of Bi Pb Sr Ca Cu Ag O (x50-1.0) prepared by the solid state reaction method. The 1.6 0.4 2 3 42x x 12 effect of Ag-doping on the Bi-(Pb)-Sr-Ca-Cu-O system has been investigated in terms of an AC susceptibility study. It was found that as the amount of Ag doping increases, the critical current density decreases. We also qualitatively discuss experimental results in the framework of the critical state model (CSM). Comparison of the observations and the results of the CSM suggests the Bean like dependence of the intergrain (matrix) depinning critical current density j on the magnetic flux density B in the low field range studied. cm The temperature dependence of the pinning strength parameter a(T) obtained from AC dissipation is in good agreement with the relation 2.37 a5a (12T /T) for undoped Bi-(Pb)-Sr-Ca-Cu-O.
Doping of Bi-Sr-Ca-Cu-O superconductors with Pb, Sn and Ag
Bulletin of Materials Science, 1991
Basic and substituted superconductors in the homologous series BizSr2Ca ._ ~Cu. 02,+4+ r, Bi 2 _x/zSr2 xi2LxCa. _ iCunO2n+4+,,and Bi:Sr 2 xL~Ca. _ iCu,,Oz.+a+~.(L = Sn, Pb or Ag, x = 0-0.4, n = 2, 3 or 4) have been synthesized. All the prepared ceramic samples show superconducting behaviour with zero resistance at T~ = 70 to 85 K. The compounds with n=3 or 4 showed onset temperature around I I5K indicating involvement of a disproportionate solid-state reaction and formation of a two-phase system. The phase involving tin or lead oxides showed similar superconducting properties. Final rapid quenching of samples contributed to preservation of the high temperature equilibria with higher solubility of tin oxide in the quaternary system Bi-Sr Ca-Cu O. Silver was not soluble but precipitated in a colloidal form at interfaces between the crystalline grains.
Journal of Physics: Conference Series, 2018
The use of silver and tellurium metals in fabricating superconductor material has been considered as promising materials. These metals are able to improve both mechanical and thermal stability. However, the fabrication of superconducting material is not merely affected by the composition of metals, but also the method in fabricating the material. To understand the effect of both factors, a study is conducted to investigate the effect of sintering time and dopant tellurium covered by silver sheet. The superconducting material was fabricated by powder in tube method composed with bismuth, lead, calcium, gold, and oxygen. The results showed that high time of sintering decreased the critical temperature of the superconducting material for over 20% from 65K to 51K. Morphological display showed that during high time of sintering caused melting of the grain even though the porosity was less. On the other hand, XRD pattern displayed that high time of sintering formed CuO and CaTeO4 compounds considered as impurities. Overall, the length of time affects the superconducting properties including critical temperature and the purity of material.
Phase formation and superconductivity in BiPbSrCaCuO
Physica C: Superconductivity, 1989
The influence of various content of Pb ++ on the formation of 2201, 2212 and 2223 phases at fixed preparation conditions has been studied for Bi-Pb-Sr-Ca-Cu-O ceramics. It has been found that Pb substitutions generally lead to reduction of unreacted CuO and 2201 phase fraction in the material. Pb helps for better growth of 2212 phase as well as for nucleation of high T c 2223 phase. The critical temperature vs the Pb content exhibits a markedly pronounced maximum.
The interaction of Ag with Bi-Pb-Sr-Ca-Cu-O superconductor
Physica C: Superconductivity, 1989
Bi-Pb-Sr-Ca-Cu-0 superconductor compounds have been doped with up to 30 wt% Ag, sintered under variable oxygen partial pressure, and characterised in terms of the electrical and crystallographic behaviour. In contrast to previous reports that claim that Ag is the only metal non-poisoning to the superconductivity of Bi-Sr-Ca-Cu-0 (BSCCO), it has been found that Ag additions to Bi-Pb-Sr-Ca-Cu-0 depress r, and J, drastically and cause a large decrease in lattice parameters when samples are treated in air or pure oxygen. However, the lattice parameters, r, and J, remain unaffected by Ag additions when samples are heat treated in 0.030-0.067 atm oxygen. It is clear that the Ag reacts with and destabilises the superconducting phase when the samples are treated in air or pure oxygen while, when the samples are heat treated in low oxygen partial pressures, the Ag remains as an isolated inert metal phase that improves the weak links between the grains. This discovery clearly shows the feasibility of Ag-clad superconductor wire. For Ag-clad superconductor tape of 0.1 mm2 cross sectional area heat treated in air, J, was measured to be 54 A/cmZ. The same specimen sintered in 0.067 atm oxygen showed that the .I, increased to 2078 A/cm'.
One and multi-step solid state reaction methods were used to prepare a high temperature superconductor with a nominal composition Bi 2−x Li x Pb 0.3 Sr 2 Ca 2 Cu 3 O 10+δ for (0 ≤ x ≤ 0.5). The effect of preparation conditions and substituting Li on Bi sites had been investigated by the use of X-ray diffraction, resistance measurements and oxygen content to obtain the optimum conditions for formation and stabilization of the 2223-phase. It has been found that intermediate grinding will force to convert and accelerate the formation rate of the 2223-phase. The morphological analyses were carried out by SEM. The results showed that the multi-step technique was appropriate to prepare the composition Bi2−xLixPb0.3Sr2Ca2Cu3O10+δ. X-ray diffraction analysis showed two phases: high-T C phase 2223 and low-T C phase 2212 with orthorhombic structure for all samples. However, the optimum concentration was found for 0.3 which improved the microstructure and had the highest T C value 130 K for the highest value of oxygen content.
The effect of Al2O3 and MgO addition on the superconducting properties of Bi, Pb-2223
THE 2ND UNIVERSITAS LAMPUNG INTERNATIONAL CONFERENCE ON SCIENCE, TECHNOLOGY, AND ENVIRONMENT (ULICoSTE) 2021
In this study, we investigate the effect of Al2O3 and MgO addition on the critical temperature of the (Bi, Pb)2Sr2Ca2Cu3O10+ (Bi, Pb)-2223 superconductors. The (Bi, Pb)-2223/ Al2O3 and (Bi, Pb)-2223/MgO composite were synthesized using a sol-gel method. BPSCCO with nominal composition was sintered at 840°C for 60 hours Phase investigation and Morphology observation were carried out by using an X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM), respectively. Critical onset temperature (Tc-onset), and critical offset temperature (Tc-offset) used the fourpoint probe technique. SEM image showed that the BPSCCO superconductor's morphological characteristics seem to dominate the microstructure for all samples. The best result was found in the (Bi, Pb)-2223 with addition 1% MgO.
Journal of Alloys and Compounds
We have carried out measurements of resistivity on Bi1.84Pb0.34Sr1.91Ca2.03Cu3.06O10 granular samples prepared by the liquid ammonium nitrate method. The standard four-probe technique was used to measure the resistivity and the critical current of the specimen. We estimated the irreversibility line from the broadening of the resistive–superconducting transition in external DC magnetic fields up to 447 mT for the sample fabricated. A non-linear Arrhenius plot of resistive tail has been found. The power law relation RBirr=B0(1−T/Tc)3/2 gives a good fit to our data obtained from zero-resistivity temperature in selected magnetic fields. We have also characterized the prepared samples in terms of XRD, SEM and critical currents.